As to paper sheets transported as a paper sheets assembly (a plurality of paper sheets is strapped by a material (band)), in order to process each paper sheet (one by one) by a paper sheets processing machine, preprocessing to remove the material is necessary. However, if the paper sheets assembly does not satisfy a predetermined specification, when preprocessing of the paper sheets assembly is performed or when paper sheets are processed by a processing machine of the paper sheets processing machine, various defects often occur. Accordingly, an operator's manual operation is required to remove the defects. As a result, in order to process the paper sheets by the paper sheets processing machine, many times and labors are necessary for the operator.